Doctor Skeptic

Pages

Monday, 8 December 2014

Science progresses because it is open to scrutiny. For
findings to be accepted, they must pass peer-review and must be presented to
other scientists for them to question, refute, or confirm. Publication in a
scientific journal (and presentation at conferences) is key to this process. However,
the number of journals and conferences have increased massively over the last
10 -20 years, and many of them are not the real thing – so called ‘predatory’
publishing and predatory conferences have sprung up everywhere. The problem
with this is that there is no clear line between what is real and what is fake.

Sunday, 26 October 2014

Hormone
replacement therapy (HRT) for post-menopausal women was thought to decrease the chance of cardiovascular
problems like heart attack and stroke. This ‘made sense’ because the risk of
cardiovascular disease in women rose sharply after menopause, indicating
that female hormones had a protective effect. Many large observational studies
supported this belief, and HRT was widely prescribed in the 1980s and 1990s.
Later evidence from large, placebo controlled, randomised trials failed to show
any cardiovascular benefit. Again, observational evidence was shown to overestimate the
effectiveness of a common medical treatment and again, practice became established before the definitive trials were done.

Sunday, 19 October 2014

The most recent casualty of the sham surgery trial, adding
to the list of operations that looked good and had good results until put to
the leased biased test, is a procedure called renal denervation (cutting the
nerves to the kidney). Years of good results showing that this procedure lowered blood pressure are now met with a blinded sham-controlled trial that showed no
significant benefit over placebo.

Thursday, 18 September 2014

One of the fundamental principles of science is that the
results of any experiment should be reproducible. Reproducibility is essential
because it means that the results can be relied upon, as they are more likely
to be true. Unfortunately, there is little fame in replicating someone else’s
study; it is also hard to get such studies funded (because they are not ‘novel’).
Consequently, many studies are not repeated and many findings stand alone
without verification from separate, independent researchers. This is a problem
because often when studies are
replicated, they fail to reproduce the original findings.

Wednesday, 10 September 2014

Patients should have a voice in medical policy and
treatment. ‘Grass-roots’ groups of patients are more likely to have that voice
heard and to effect change if they are organised and well funded. Patient
advocacy groups can therefore be more effective if they accept industry
(pharma) funding. However, such groups can also serve the interests of the
industry doing the funding. It is even better for the industry, however, if
they organise the grass-roots patient advocacy group from the start; so-called ‘astroturfing’.

Sunday, 17 August 2014

In the 1940s and 50s (tapering into the 70s and 80s) tens of thousands
of prefrontal lobotomies (severing the front part of the brain) were performed
in Europe and North America for many types of mental conditions. It was done
because doctors at that time believed that it worked, and they didn’t have many
effective alternatives. However, it didn’t work, it made people worse and it even
killed a few, despite a Nobel prize being awarded to one of the developers of
the procedure.

Monday, 11 August 2014

This story is about a procedure that made sense and had
supporting evidence, became common practice, but was later discontinued because
a high quality study showed it to be ineffective. The story of extra-cranial
intra-cranial bypass surgery ticks all the boxes: overestimation of benefit, seduction
by the theory, unrecognised bias in studies, and just plain ineffectiveness despite our best effort and beliefs.

Friday, 27 June 2014

Wouldn’t it be great if there was a cheap, non-proprietary,
readily available treatment for patients with heart attacks (acute myocardial
infarction - AMI)? That’s what doctors wanted to believe, so when they saw the
early results of magnesium therapy, they did exactly that. Magnesium therapy
for AMI has been labelled a “lesson
in medical humility”, but I see it as another example of the pervasive bias
amongst researchers, doctors and the public that leads them to overestimate the
effectiveness of medical therapies. Put simply, it was another case of ‘believing
is seeing’.

Sunday, 22 June 2014

The idea is that experiments are first performed in the lab, are
then performed in animals, and these experiments inform the eventual human studies.
As a (seemingly) necessary step in this chain, animal experiments are (rightly or
wrongly) tolerated based on their eventual benefit to humans. Animal studies
however, are not good predictors of human trials, often do not inform human
trials, and are methodologically inferior to human trials, so much so, that the
results from animal studies are unreliable and biased. In other words, animal studies
are often of no benefit to humans. Arguably, they do not benefit humans at all,
let alone enough to justify their use. We either need to fix the problem or get
out of the animal research game.

Sunday, 27 April 2014

When you raise your arm, the top of your humerus, where the
rotator cuff tendons attach, “impinge” against your acromion. When this hurts,
it is called impingement syndrome. “Decompressing” the joint by taking some
bone off the acromion (an "acromioplasty”) makes sense, and seems to work well.
The operation has been around for a long time, and there have been many studies
looking at different ways of doing this operation, but very few studies looking
at whether or not it works better than not operating. Interestingly, all of the
studies that have been done conclude that
this operation adds nothing.

Testing Treatments is a book, and Testing Treatments
Interactive (http://www.testingtreatments.org/)
is a website that contains the book, with live links and added information. It
is a valuable reference tool for the layperson and also useful for health
practitioners who are not well versed in evidence-based medicine. The book
tells you why it is important to test treatments, how this type of testing
should be done, and how to make research better and more useful to future
patients.

Sunday, 16 March 2014

What if I could produce an experiment that concluded that
listening to an old song could make you younger? Not feel younger, but be
younger. Impossible, of course, but the story of how this can be achieved is a
great example of how easy it is to produce statistically significant findings
in science. All you need is enough 'wriggle room' in the data and a pre-conceived notion of what the results will be. Like ghosts in The Sixth Sense,
scientists often only see what they want to see.

Monday, 10 March 2014

As a junior doctor in Australia, the country with the deadliest snakes and spiders in the world, you quickly learn where the antivenoms are kept. Now it appears that the deadliness of these critters is less than we thought, and the benefits of the anti-venoms are under question, or have been proven to be ineffective.

Sunday, 23 February 2014

When treatment choices are limited or when true
effectiveness is not clear, patients want hope: they want to have a chance to
get better. Doctors hold this valuable commodity, and dispense it on demand,
for a fee, after which they claim any perceived improvement as
being due to their efforts. Even when a treatment is not proven to be
effective, or when it is proven to be no better than placebo, doctors too
easily fall into the role of hope-peddler, without considering the hidden costs or unintended consequences.

Friday, 24 January 2014

Allow me to make an assertion: breast cancer survival is not
influenced by surgical excision of the primary tumour. This goes against the prevailing
wisdom that cancer is cured by removing it, but that kind of thinking is
simplistic and at odds with much of the evidence. Lets walk through that evidence.

Thursday, 2 January 2014

I have previously written that knee arthroscopy for
osteoarthritis is no more effective than alternatives, including placebo. One
criticism of those studies was that arthroscopy is usually done for a torn
meniscus (often incorrectly called a torn cartilage) rather than arthritis,
despite the facts that the original sham trial of arthroscopy included patients
with meniscus tears, and later comparative studies looked specifically at
patients with torn menisci. Now, however, we have evidence from a
placebo-controlled trial of arthroscopic surgery performed specifically for a
torn meniscus in patients without
arthritis. Evidence that shows that while most patients improve after surgery, they
improve equally well after placebo surgery.

Friday, 20 December 2013

In the early days of surgery, surgeons tried to out do each
other in their ability to perform bigger operations, and mastectomy was no
exception. For breast cancer, excising the tumour seemed like logical
treatment, at least for local control. It also seemed logical that if some excision was good, more excision was better. So simple
tumour excision soon gave way to simple mastectomy, which gave way to total
mastectomy, which gave way to radical mastectomy, which gave way to things like
the ‘extended’ radical mastectomy and the ‘supra-radical’ mastectomy (which
included excising the chest wall, amongst other things). Yet, all of this
effort was done without properly evaluating the effectiveness – it was all
based on what seemed like a good idea.

Friday, 29 November 2013

This book is not an opinion piece and it holds no new
information, but it is as important as any other book I have reviewed because it
aims to narrow the gap between practice and evidence in medicine by teaching
doctors the science of medical practice; in other words, how to recognise and
weigh error, and objectively appraise the scientific evidence for clinical
practice.

Sunday, 10 November 2013

It seems I will never run out of examples of treatments that
sound obviously effective in theory, fall into common use based on the strength
of the biological mechanism, and yet they fail to show a significant benefit
when put to the test. The story of the IVC filter is one of these.

Deep venous thrombosis (DVTs, clots) in the leg can
dislodge, traveling up through the main vein in the pelvis and abdomen
(inferior vena cava, IVC), through the heart and then embolise in the lungs
(pulmonary embolus, PE), sometimes causing rapid death. An IVC filter is a wire
cage placed in the IVC that snares clots that have broken free from the leg
veins, before they can travel to the lungs. The device has been used for
decades, but without much evidence of benefit, as this recent
report tells us.

Search This Blog

Loading...

About this blog

This blog explores the true effectiveness of medical interventions, established through scientific study, as opposed to the perceived effectiveness. This highlights our overestimation of the benefits and underestimation of the harms from these interventions.

About Me

Why be skeptical about medicine?

Doctors and skeptics are often critical of alternative medicine and other non-medical healing practices because they are not well supported by scientific evidence. This is appropriate.What is inappropriate is the acceptance of medical practices (established and new) without a requirement for the same level of scientific support.The evidence supporting many medical practices is less than many people suppose, and similarly, the harms from medicine are often under-appreciated.We need to ask the same question of medicine that we would ask the alternative practitioner: what is the evidence? But we need skills to be able to critically appraise that evidence, because unlike (say) homeopathy, medical evidence is based on science. This is part of the problem because for many, being scientifically based is reason enough for a treatment to be accepted as true; assuming that a medical treatment works is our default position. This, and the other biases that creep into medical science on so many levels, at least partly due to our keenness to see it work, are the reasons for looking at medicine with a skeptical eye.